The invention relates to a wheel bearing and a constant velocity joint, wherein the outer ring of the constant velocity joint is connected to the inner ring flange of the wheel bearing via a positive-locking connection to transmit torque from the constant velocity joint to the wheel bearing via this positive-locking connection.
Integration of parts and an associated demand for lightweight construction are long known requirements in automobile construction. This also applies to the wheel bearing arrangement and to the attempt to integrate as many functions as possible into the wheel bearing arrangement from its surroundings.
Intensive effort has been made in integrating a constant velocity joint into a wheel bearing. A construction unit comprising a constant velocity joint and a wheel bearing is shown in DE 23 29 554 A1. The constant velocity joint is of a solid type of construction and is connected directly to the inner ring flange via a splined shaft profile. There are problems with this design. The solid construction of the outer ring of the constant velocity joint, in combination with the additional splined shaft profile, has a very large diameter. As a result, the wheel bearing lying on the outside has to be of large design. A further problem is that the tooth system extends over the entire axial length of the constant velocity joint. This prevents the outer ring of the constant velocity joint from yielding elastically in the face of the deformations which occur, due to the production tolerances in the tracks of the balls of the constant velocity joint. These constraining forces lead to additional undesirable heating in the constant velocity joint and to increased wear.
A constant velocity joint having opposed curved tracks is shown in DE 19831012 A1. This constant velocity joint has a flange for transmitting the torque. Since this constant velocity joint is designed as a sheet-metal part in a lightweight type of construction, it also requires a second small flange in order to achieve sufficient rigidity. This constant velocity joint with opposed tracks is therefore arranged next to the wheel bearing when it is fitted in place.
The object of the invention is to provide a novel connection between the wheel bearing and the constant velocity joint, which connection meets the requirements for lightweight construction, is simple to produce and avoids constraining forces in the constant velocity joint.
A constant velocity joint is located inside the inner ring flange of the wheel bearing around the joint. According to the invention, there is a tooth system inside the inner ring flange of the outer surrounding wheel bearing, to which the torque is transmitted. The teeth of the tooth system extend axially across the inner ring flange, and have circumferentially leading and trailing tooth flanks. The tooth system is designed to mesh with the generally complementary contours of the sheet-metal outer ring of the constant velocity joint in defined sections so that those elements rotate together. These contours of the outer ring of the joint are obtained during the sheet-metal working. The tooth system does not come in contact in the end region of the track running radially inward.
There are surprising advantages of this tooth system located in the inner ring flange.
The outer contour of the outer ring of the constant velocity joint, which contour is obtained during the sheet-metal working for producing the tracks for the torque transmitting balls in the outer ring of the joint, is utilized for the transmission of the torque from the constant velocity joint to the wheel bearing. This provides a construction which is light weight and which has a small diameter because the additional tooth system shown in the prior art is dispensed with. Further production operations on the outer contour of the outer ring of the constant velocity joint are therefore unnecessary.
The flanges shown in the constant velocity joint in DE 198 31 012 A1 located on the outer ring of the constant velocity joint can be dispensed with. The task of the larger flange is to transmit the torque, and the task of the second flange is to increase the rigidity of the outer ring of the constant velocity joint. This necessary rigidity of the outer ring of the constant velocity joint is now replaced by the tooth system in the inner ring flange. In this case, the tooth system in the inner ring flange supports the outer ring of the constant velocity joint only at the flanks, i.e., the circumferentially leading and trailing surfaces, of the tracks of the outer ring of the joint. That end of each track which runs radially inward is exposed. There is the requisite elasticity of the outer ring of the constant velocity joint in order to keep all the torque transmitting ball bearings uniformly in the tracks in a pivoted constant velocity joint. The elasticity in this case is required in order to compensate for production tolerances in the constant velocity joint.
Due to the tooth system meshing in sections only between the wheel bearing and the constant velocity joint, heat transfer between these components is reduced. This has a positive effect on the service life, particularly of the wheel bearing.
The tooth system in the inner ring flange is simple to produce. This tooth system can be produced during cold or hot working for producing the inner ring flange. Broaching or milling processes are also suitable for producing this tooth system. Due to the design of the tooth system (e.g. straight or curved) in the inner ring flange, the position of the torque-transmitting area between the outer ring of the constant velocity joint and the tooth system of the inner ring joint can be freely selected.